The Fischer Tropsch process for converting synthesis gas comprising carbon monoxide and hydrogen into a variety of hydrocarbons and oxygenated hydrocarbons has been investigated for some time, and a variety of products have been produced by this technique. Examples of products include C.sub.2 to C.sub.6 olefins, lights, e.g. C.sub.1 -C.sub.2 paraffins, C.sub.6 to C.sub.10 hydrocarbons e.g. gasoline and kerosene, as well as oxygenated hydrocarbons, such as, methanol, dimethyl ether, various esters, acids and alcohols. Selectivity to a particular product is influenced substantially by the process conditions utilized, e.g. in terms of temperature and pressure as well as the catalyst utilized in the reaction.
U.S. Pat. No. 4,328,129 discloses a Fischer Tropsch process for producing dimethyl ether and methanol in high selectivity by contacting a gaseous mixture of carbon monoxide and hydrogen with a rhodium-molybdenum catalyst, the condition being monitored to favor production of these two materials. In the background portion of the patent, it is indicated that U.S. Pat. No. 3,941,819 discloses the production of dimethyl ether over a calalyst system consisting of platinum supported on alumina.
U.S. Pat. No. 4,098,809 discloses a process for producing dimethyl ether in a Fischer Tropsch process utilizing a methanol synthesis catalyst, such as a copper base or chromium-zinc base catalyst.
U.S. Pat. No. 3,894,102 discloses a process for converting synthesis gas to dimethyl ether and then subsequently to a high octane gasoline. The first stage of the process involves reacting carbon monoxide with hydrogen in the presence of a mixed methanol synthesis and acidic dehydration catalyst. Temperatures from about 300.degree.-700.degree. F., elevated pressures, e.g. up to about 10,000 psig, and space velocities of at least 500 GHSV are used in the first stage to produce dimethyl ether.
U.S. Pat. No. 4,177,167 discloses a process for producing dimethyl ether by the catalyst reaction of carbon monoxide and hydrogen utilizing a mixture of oxides or salts of metals such as aluminum, chromium, lanthanum, manganese, copper or zinc as a catalyst.
U.S. Pat. No. 4,154,751 discloses a series of supported potassium or rubidium-Group 8 metal cluster catalysts for producing a variety of components in a Fischer Tropsch process. Examples of precursor bimetallic cluster complexes include potassium-iron carbonyl compounds, potassium-nickel carbonyl compounds and potassium-platinum carbonyl compounds though the corresponding rubidium complexes are also shown. These catalysts produce predominantly hydrocarbon products with little or no oxygenate selectivity.
Great Britain No. 2,093,365, describes a catalyst consisting of copper, zinc and alumina which is effective for the conversion of synthesis gas to dimethyl ether.